Osaka is 7 hours ahead of Prague
Best overlap: 8:00 AM to 11:00 AM in Prague is 3:00 PM to 6:00 PM in Osaka.
Aim for 8:00 AM to 11:00 AM Prague time — that's 3:00 PM to 6:00 PM over in Osaka. You share roughly 3 hours a day. That's enough for regular meetings, but treat the window as prime time and guard it. Remember that Prague shifts for daylight saving and Osaka doesn't, so recalculate the overlap after each clock change.